Tilt apparatus

ABSTRACT

A TILTABLE PLATFORM UNIT SUPPORTED ON A BASE UNIT IS TAUGHT. BOTH THE PLATFORM UNIT AND BASE UNIT ARE EQUIPPED WITH LINEAR STYLE TRACKS. A TRACK FOLLOWER IS GUIDED IN A PREDETERMINED PATH BY THE TRACK ON ONE OF THE UNITS AND ACTS COOPERATIVELY WITH THE TRACK ON THE OTHER UNIT TO CAUSE THE TILTING ACTION. THE TILTABLE PLATFORM UNIT IS CAPABLE OF MOVEMENT IN A HORIZONTAL DIRECTION WITHOUT TILTING DURING A PORTION OF THE MOVEMENT OF THE TRACK FOLLOWER. THE COMBINATION OF BOTH HORIZONTAL MOVEMENT AND A TILTING CAPABILITY FOR THE PLATFORM UNIT IS ACCOMPLISHED BY EMPLOYING A SPECIAL PIVOT ASSEMBLY BETWEEN THE PLATFORM AND BASE UNITS. THE PIVOT ASSEMBLY INCLUDES A GUIDE PART, AND A GUIDE FOLLOWER PART COOPERATIVELY ASSOCIATED WITH THE GUIDE PART. THE GUIDE PART IS FIXED TO ONE OF THE UNITS (THE BASE UNIT), AND THE GUIDE FOLLOWER PART IS FIXED TO THE OTHER UNIT (THE PLATFORM UNIT). THE APPARATUS ALSO INCLUDES A FOOTBOARD ASSEMBLY WHICH IS COLLAPSIBLE UNDERNEATH THE PLATFORM UNIT BUT MOVABLE INTO A FOOT SUPPORT POSITION AT ONE END OF THE PLATFORM UNIT PRIOR TO TILTING THE PLATFORM FROM THE HORIZONTAL TO AN APPROXIMATELY UPRIGHT OR VERTICAL POSITION. THE FOOTBOARD ASSEMBLY IS PIVOTALLY ATTACHED TO THE AXIS OF THE MAJOR PIVOT BETWEEN THE PLATFORM UNIT AND BASE UNIT. AN ACTUATING MEMBER FIXED TO THE TILTABLE PLATFORM UNIT COOPERATES WITH AN ACTUATING TRACK ON THE FOOTBOARD ASSEMBLY FOR MOVEMENT OF THE FOOTBOARD TO THE FOOT SUPPORT POSITION AND FOR WITHDRAWAL OF IT AFTER TILTABLE PLATFORM UNIT IS RETURNED TO THE HORIZONTAL FORM A TILTED POSITION.

Oct. 5, 1971 c w OJA ETAL TILT APPARATUS 3 Sheets-Sheot 1 Filed June 16, 1970 MAM T J F Y N00 5 E F. N vwm M W. 5 a T L A R R 3 A T Oct. 5, 1971 c. w. OJA EI'AL T ILT APPARATUS 5 Sheets-Sheet 2 Filed June 16, 1970 INVENTORS CARL W 0J4 RICHARD L SCHEUERMAN THE/R ATTORNEY Oct. 5, 1971 Q w, OJA ET AL 3,609,779

TILT APPARATUS Filed June 16, 1970 3 Sheets-Sheet 5 Ha I] INVENTORS CARL W. OJA RICHARD L. SCHEUERMAN maww THE II? A TIURNE Y United States Patent US. Cl. 5-62 22 Claims ABSTRACT OF THE DISCLOSURE A tiltable platform unit supported on a base unit is taught. Both the platform unit and base unit are equipped with linear style tracks. A track follower is guided in a predetermined path by the track on one of the units and acts cooperatively with the track on the other unit to cause the tilting action.

The tiltable platform unit is capable of movement in a horizontal direction without tilting during a portion of the movement of the track follower. The combination of both horizontal movement and a tilting capability for the platform unit is accomplished by employing a special pivot assembly between the platform and base units. The pivot assembly includes a guide part, and a guide follower part cooperatively associated with the guide part. The guide part is fixed to one of the units (the base unit); and the guide follower part is fixed to the other unit (the platform unit).

The apparatus also includes a footboard assembly which is collapsible underneath the platform unit but movable into a foot support position at one end of the platform unit prior to tilting the platform from the horizontal to an approximately upright or vertical position. The footboard assembly is pivotally attached to the axis of the major pivot between the platform unit and base unit. An actuating member fixed to the tiltable platform unit cooperates with an actuating track on the footboard assembly for movement of the footboard to the foot support position and for withdrawal of it after the tiltable platform unit is returned to the horizontal from a tilted position.

This invention relates to new apparatus and to new sub-assemblies of elements, with new and cooperative interrelationships between parts, to thereby provide improved and new functions. The invention provides a tiltable table or platform unit supported on a base frame structure. It provides a variety of novel actuating means for movement of leg, arm or platform parts in a predeter mined manner between two limits or extremes of motion.

The invention further provides a novel cam and cam pusher arrangement for accomplishing tilting of a platform unit. It provides a special footboard assembly of elements, plus means for combining this assembly with tiltable platform action so that the footboard remains normally in a recessed location but moves into position for foot support prior to actual tilting action of the platform. It provides means whereby the platform is caused to move toward the footboard after the footboard is raised into position for foot support purposes; and this motion in no way forecloses subsequent tilt of the platform.

Such apparatus as taught herein is useful in a variety of applications. Tilt platforms of the invention (whether as tables, stretchers, beds, or the like) are useful in the health arts, to handle and treat patients. The various actuating mechanisms of the invention are present in the preferred tilt platforms, but also are useful as part of other apparatus arrangements, such as, for example, in the conveying art where limited movement feeders to a main line are needed.

3,669,779 Patented Oct. 5., 1971 Tiltable platform assemblies are of course well known; see, for example, the following illustrative patents: 1,228,- 953; 1,874,582; 1,925,425; 2,222,888; 2,534,623; 2,568,- 236; 2,680,046; 2,816,806; 2,828,172; and 2,932,038.

Although tiltable platform units supported on base structures have been heretofore known, none insofar as is known has possessed the novel advantageous features and interrelationships characteristic of apparatus of this 1nvention.

One of the most unique features of the present apparatus is the novel tilting mechanism. Two linear style tracks, one on the tiltable platform and the other on the base unit of this apparatus, with a track follower guided by the track on one of the units, act cooperatively for the tilting action. The track follower (guided by the track on one of the units) follows and cooperatively acts with the track on the other unit to cause the tilting action.

Ordinarily, the hinge of pivot between a tiltable platform and base structure would be expected to be fixed. But in the preferred embodiment of the apparatus of this invention, such a fixed hinge of pivot is not present. In this apparatus, the tiltable platform is capable of movement in a horizontal direction without tilting action. This is believed to be an entirely new and highly unusual feature with respect to tiltable platform apparatus, especially in the way the movement and tilting is accomplished here- 1n.

Another especially interesting feature of the preferred embodiment of this apparatus is that of the collapsible footboard arrangement. Footboards for tiltable tables have been suggested heretofore, as for example illustrated in McDonald US. Pat. No. 2,828,172 and Wilent U.S. Pat. No. 1,925,425. But heretofore known footboards are clumsy in arrangement and interfere with the comfort of the patient as well as the security feeling of the patient. As a patient rests in a horizontal position, his body tends to lengthen slightly upon relaxation; and this is particularly characteristic also of ones feet, which upon relaxation assume an angular position. The angular position is not perpendicular to the length of the body. A relaxed person lying horizontally on a platform finds it uncomfortable if a footboard simply swings or arcs into a position where it was when the patient first stood on it at the time he was tilted from a substantially vertical position to the horizontal resting position. In the present apparatus, the footboard does swing or are upwardly into a foot support position, but does so at a location removed from the patients feet. Thereafter, the horizontally-oriented platform on which the patient is resting, and the footboard, move together. In the preferred teaching herein, the horizontal platform on which the patient is lying is the part which moves toward the footboard. As this occurs, the footboard presses against the patients feet. Elements of apparatus then cause the footboard and platform to more or less lock together. The locked relationship between the two is maintained while the entire assembly of platform and footboard tilts back to an upright position. Then the patient simply steps way from the apparatus. Thus the patient is returned to an upright position without exerting effort on his part and without the assistance of others. Since the assistance of others to raise him from the horizontal to an upright position is unnecessary, the hazard of inept assistance is obviated.

A still further advantageous feature of the preferred embodiment of tilt platform apparatus as taught herein is that of its adjustability in height. Ordinarily, complex or expensive apparatus elements would be required to adjust the height of tiltable apparatus, if such adjustability is provided at all; and the base structure for such apparatus normally has been extremely bulky. Generally, reliance has been placed upon immense mass to maintain the base stable during tilting of a platform. The base unit structure of the present apparatus, however, is so designed in the preferred embodiment that stability is actually gained without great bulk or mass or weight. Additionally, the spacing of support legs, and the preferred type of legs, make it possible for convenient and relatively simple, but sturdy and reliable, means to be incorporated in the apparatus for adjusting the height of the base. This in turn effects adjustment of the height of the tiltable platform; and such a result is taught herein for any angle of tilt of the platform, or whether or not it is tilted.

Several other benefits and advantages of this invention will readily be apparent upon study of this specification.

The invention will be described by reference to the drawing made a part hereof wherein:

FIG. 1 is a schematic perspective view of a mobile tiltable treatment table according to the invention;

FIG. 2 is a schematic cross-sectional view taken on line 2-2 of FIG. 1;

FIG. 3 is a schematic enlargement of significant elements of apparatus within the housing of the height adjustability mechanism for the base unit of the apparatus;

FIG. 4 is a schematic sectional view through a leg on the base unit of the apparatus;

FIG. '5 is a schematic cross-sectional view through line 55 of FIG. 2, illustrating features of the platform tilt mechanism, with background elements omitted to improve clarity;

FIG. 6 is a schematic cross-sectional view through line 6-6 of FIG. 2, illustrating features of the upper structure of the base unit of the apparatus, with background elements omitted to improve clarity;

FIGS. 7 and 8 are detailed schematic side views of the footboard assembly and associated elements;

FIG. 9 is a schematic side View illustrating the tilting platform action, with the solid lines illustrative of the platform unit in a horizontal position and the footboard appropriately collapsed, with the dash line phantom view illustrative of the position of the footboard assembly and tiltable platform immediately prior to tilting action, and with the interrupted solid line phantom view illustrative of a tilt position of the tiltable platform and footboard assembly;

FIG. 10 is a schematic cross-sectional view (along line 22 of FIG. 1), with most background elements removed or omitted, illustrating elements which provide a pivot look at the major pivot shaft between the platform and base unit, as well as elements which provide a safety feature against over-tilting;

FIG. 11 is a schematic view in perspective, looking toward the underside of the tilted platform at the juncture between the platform unit and base unit; and

FIG. 12 is a schematic layout of electrical wiring for power means preferably incorporated as part of the composite apparatus.

The specific preferred embodiment of the invention illustrated in the drawing is to be noted as made up of several major groupings or sub-assemblies of elements. For convenience, these groupings broadly may be outlined as follows: A base unit 10, a tiltable platform unit 11, a footboard assembly 12, and a major pivot assembly 13. Each grouping contains elements interrelated in structure and function with elements of other groupings. Basically, the platform unit 11 is an assembly of elements arranged to tilt or pivot with respect to the base unit assembly 10. The tilting occurs at the major pivot assembly 13. Prior to tilting of the platform unit 11 from a horizontal position to an upright position, the footboard assembly 12 is actuated by special linkages which raise it into an operable position at one end of the tiltable platform.

The base unit 10 will first be described (see FIGS. 1-4, inclusive). It is preferably adjustable in height, and suitably consists of a lower stand member 14 or base, plus an upper frame member 15 or top structure. The top structure 15 is adjustable in height with respect to the lower member 14. The lower member .14 and the upper member 15, together, comprise what is herein called the base unit. While a pedestal or other type of base unit, with or without height adjustability, may be employed, much greater mobility for the apparatus, consistent with strength and lightness in weight, is realized when the base unit 10 is formed with spaced and braced leg elements, as illustrated in the drawing.

The lower stand member 14 of the preferred base unit 10 includes four legs 16 spaced and braced in rectangular arrangement, suitably by longitudinal braces 17 and lateral braces 18. The upper frame member 15 or top structure, which is also part of the composite base unit 10, is supported by four tubular leg members 19 cooperatively connected to the four legs 16 of the lower stand. Tubular leg members 19 curve at the upper extremity thereof and extend as horizontal tubes 20 to a control mechanism box 21 at a central location in the upper member part 15.

Elements within the control mechanism box 21 are illustrated in FIG. 3. As there shown, the elements include a plunger 22 for each horizontal tubular leg section 20. Each plunger 22 telescopes slidably within the horizontally-oriented upper end 20 of the tubular leg members. In other words, each plunger 22 is slidable telescopingly within a horizontal plunger-receiving section 20 of the tubular members. Each such plunger 22 is fixed to a bracket 23, which, in turn, is adjustable incrementally in a horizontal direction by virtue of its threaded mounting upon a horizontal worm or screw means 24. Worm means 24 is suitably, but optionally, powered by electrical means 25 (e.g., a reversible or two way electrical motor) mounted on the upper frame 15 of the base unit 10.

Each base leg 16 of the lower stand 14 of the base unit 10 includes within it (see FIG. 4) a stem or solidly fixed abutment member 26 extending telescopingly into the bottom open end of tubular member 19.

Between the abutment stem 26 in each base leg 16 (FIG. 4) and lunger 22 at the uppermost horizontal end 20 (FIG. 3) are a series of discreet solid balls 27 in direct abutting pressure-contact and in lineal alignment within the tube members 19. Thus, as a plunger 22 at the uppermost end is slid into the tubular members 20, pressure is applied upon the solid balls 27. The force relaxing this pressure causes the tubular leg members 19 (integral with horizontal tube parts 20) to be pulled or moved upwardly out of the base leg elements 16. Thus, the top structure 15 of the composite base unit 10 is elevated. Withdrawal of the plungers 22 from the horizontally oriented portion 20 of the tubular members relaxes pressure on the aligned balls 27, and causes the top structure to lower by gravity (and the cable 28 connection to be described) toward the lower member 14 of the base unit 10.

Cables 28 hold the upper member 15 and lower member 14 of the base unit 10 together, permitting the entire base unit 10 to be lifted as a single structure. Specifically, a cable 28 extends from a fixed connnection 29 to each plunger 22 (or bracket 23) through a cable guide 30 to a fixed connection 31 to the legs 16 (that is, associated with legs 16 or stem 26) of the lower member "14. These cables unify the lower stand 14 and top structure 15 and maintain a more or less constant pressure on the aligned balls 27. Additionally, cables 28 serve to lift the lower member 14 of the base unit, or pull it upward from contact with a floor, when the weight of the upper structure 15 is supported on castors 38 and the withdrawal motion of plungers 22 from tubes 20 is continued for a short distance, such as a centimeter or so. Such withdrawal motion pulls on cables 28 attached to bracket 23; and this action lifts the lower unit 14.

Further details for a specific structure such as just outlined, permitting adjustability of the height of an upper structure 15 with respect to a lower stand or base member 14, are set forth in U.S. Patent No. 3,283,732, issued Nov. 8, 1966, the disclosure of which is herein incorporated by reference. Of course, other or alternate means may suitably be employed to accomplish height adjustability for a composite base unit 10.

Mounted upon the upper frame part 15 of the composite base unit is a track-support structure broadly identified as 32 in FIG. 2. This structure 32 holds two parallel linear-style track members or rail-like members 33 and 34 in laterally spaced and braced condition (see FIGS. 1, 2, 5 and 6). These parallel rail members 33 and 34 are, in most cases, aligned with the longer length of the base unit. They are mounted on depending frame elements 35, which are in turn fixed to the upper member part of the base unit 10. For example, the upper part 15 of the base unit 10 may have a rigid horizontal platform or table top 36 to which the frame leg-like elements are fixed. Instead of a rigid table top 36, a network of brace members may support the control mechanism 21 for adjusting the height of the upper structure of the base unit 10, as well as the depending frame supports 35 for tracks 33 and 34. Leg-like frame elements 35, and consequently rails 33 and 34, are held in laterally braced or supported condition by lateral braces 37 extending between elements 35 at each end of the track-support structure 32, as illustrated in FIG. 6.

Frame leg-like elements 35 suitably extend below the tracks 3.3 and 34, and are suitably equipped with castors 38. Elements 35 also arepreferably of sufficient length so that, as the height adjustable mechanism for the base unit 10 is adjusted to the lowest level, castors 38 make contact with the floor and support the entire upper frame structure 15 of the base unit 10. At the same time, cables 28 (extending between plungers 22 and the lower base stand member 14) pull the lower base stand member 14 slightly off the fioor (e.g. a centimeter or so) and permit the entire apparatus to be rolled about on castors 38.

A yoke bar 39 of a truck assembly extends transversely between rails or tracks 33 and 34 (see FIGS. 2 and 5). Truck assembly bar 39 is equipped at each end with a member 40 which rides the rails 33 and 34 as the yoke or truck bar 39 is moved along the length of the rails 33 and 34. Suitably, members 40 riding the rails 33 and 34 are little rollers 40, or bearing members.

Outwardly from the roller bearing members 40, at each end of the yoke or truck 39, are cam followers or wheels 42. Wheels 42 are preferably freely rotatable on shafts 41 fixed to the yoke. The function of these wheels 42 will later be described in detail. For the present, sufiice it to say that they act as cam pushers or track followers, and press against a further track, also herein called a cam, which is on the tiltable platform 11 of the apparatus.

Means for moving yoke 39 along the length of rails 33 and 34 may consist of a worm shaft 43,- which extends parallel to the rails 33 and 34 at a location intermediate between them. Shaft 43 is suitably mounted in a journal box or bearing 44 on lateral brace 37 at one end of it (see FIGS. 2 and 6). The other end of shaft 43 is connected to power means 45 (see FIG. 2). Power means 45 suitably is a reversible or two way electrical motor, mounted on any suitable brace part of the upper member structure 15 of the base unit 10. Gear reduction and the like, not shown, may be present to reduce the rotation of the worm shaft 43 as compared to the rotation of motor 45. It will be evident that, as worm shaft 43 rotates, yoke 39 is moved along the length of worm shaft 43: and this simultaneously causes the bearing members 40 to ride the rails 33 and 34. Thus, bearing members 40 take the linear-style path provided by the position of the rails 33 and 34. This may be more fully appreciated by realizing an alternate optional arrangement. For example, the end of worm shaft 43, shown as mounted in journal box 44, may be free of a mounting and therefore free-floating. Thus, both worm shaft 43 and its power means 45 may,

6 if desired, be mounted on a single cross bar for limited pivot type action; and this expedient, or an equivalent, is necessary whenever the arrangement of illustrated elements is more or less maintained but curvilinear tracks are chosen for the tracks or rails 33 and 34.

The second major grouping of elements is that referred to as the tiltable platform unit 11. This unit generally will have a fiat or substantially flat elongated and rectangular table top or surface member 46. Preferably this member is padded for comfort reasons. The table top 46 is connected to the base unit (that is, to the upper member or top structure 15 of the base unit 10) through the major pivot assembly 13.

Depending from each lateral edge portion of the tiltable platform or table top 46 are large cams 47 or camlike or skirt members. These are fixed to the table top, preferably at a location under it near lateral edges of it. The lower edge of the large cams 47 may be noted to resemble a french curve in general outline. This structure is preferred for reasons which will be explained later. It is this lower edge of the large earns 47 which is characterized herein as the track part of the tilt platform unit. It must be appreciated, however, that a suitable equivalent track may be formed by braced rail-like members having a contour suitably such as that provided by the lower edge of the large cams 47 illustrated in the drawing. Still further, an elongated slot member might be braced and mounted to provide the necessary track means fixed to the tiltable platform 46. This track means fixed to the tiltable platform 11 is characterized as linear in style. It is, of course, preferably curvilinear, as illustrated; but a more or less straight track on the tiltable platform, and a curvilinear track on the base unit, could be used, if desired. Also to be recognized is the fact that a single (instead of a dual) track may be employed, especially when the principles herein are incorporated in a tilt platform of modest size for some specialized use such as a tiltable discharge chute or the like.

In the preferred embodiment, the tiltable platform 46 is adapted to be moved horizontally a distance before it is tilted at the pivot assembly 13. Thus, if desired, roller bearings 48 may be provided between the tiltable platform 46 and brace members or table 36 of the top structure 15 of the base unit 10. These bearings 48 may, of course, be fixed either to the underside of the tiltable platform 46, so as to elevate with it as it is tilted; or may be fixed to upper portions of the top structure 15 of the base unit 10. They simply assist in providing a low friction support for horizontal shifting of the tiltable platform 46.

Where desired, belt loops or equivalent fasteners 49, for strap fastening, may be located along lateral edges of the tiltable plateform 46. It is sometimes necessary to strap patients to the platform during treatment or during the tilting operation. By strapping the patient to the plat form during the tilting operation, his sense of security is increased; and strapping may be necessary in some cases simply to restrain hazardous patient movements.

An advantageous but option feature of the platform is an adjustable forehead-rest device which provides a face opening. This device consists of a cut-out section of the platform to form a slide member 50. Member 50 is equipped with lateral slide slots 51 which receive flange rails 52 mounted on the face rest opening of the platform 46. Thus, slide adjustability is provided.

As the third major grouping of elements, reference is made to the retractable footboard assembly 12, which is an optional but preferable part of the total apparatus. This arrangement of elements is useful in a variety of applications (e.g. as in feeding to a conveyor) independent of the tiltable platform per se. It is shown oriented at one end of the rectangular tiltable platform unit 11. The end selected is that which becomes the lowermost portion on tilting to an upright position. The elements forming the footboard grouping 12 are pivotally fixed to one end of the unit 10 (i.e., to the upper members or top structure 15 of the base unit of the composite apparatus); and these elements are coordinated for cooperative action with the tiltable platform unit 11.

Suitably, the footboard assembly 12 (FIGS. 1 and 2 for general features and FIGS. 7 and 8 for details) is pivotally afiixed to the top structure of the base unit 10 at or near the location of the major pivot assembly 13. Preferably, it is pivotally fixed at a location coinciding with the axis of pivot or tilt between the tiltable platform unit 11 and the brace unit 10. Thus, the footboard legs 53 (see FIG. 7 for details) for the retractable footboard 54 are mounted at one end (and in spaced relationship) by a pivot connection to the axis 55 of the major pivot shaft. This shaft 55 is fixed transversely across an upper end of the top structure 15 of the base unit 10. Suitable alternate means for pivot connection of the footboard leg members 53 may consist of brackets and pins at any suitable location providing a pivot or hinged attachment to an end portion of the top structure 15 of the base unit 10.

A footboard 54 extends between the footboard leg members 53 and is attached pivotally at its sides to the outermost end portions of the leg members 53. The outermost end portion of legs 53 is opposite the ends pivotally mounted to the base unit 10. The pivotal attachment between legs 53 and a footboard 54 suitably consists of a pin 56 between a leg bracket 69 and the footboard.

On each footboard leg 53 is a slide member 57 adapted to slide lengthwise of the footboard legs. Means, such as springs 58 bias the slide members 57 toward the footboard 54. Footboard brace arms 59 are pivotally or hingedly secured at one end to the slide members 57 and at the other end to the footboard 54 at a location spaced from the pivot attachment S6 of the footboard to the footboard leg 53.

Special foldable arms 60 and 61 extend between the slide members 57 and a bracket 62 attachment on the tiltable platform 46. These foldable arms 60 and 61 are pivotally attached at their ends; and they are each equipped with a stop member 63 at the hinge of their folding so as to prevent a dead center positioning of the two links or lengths making up each foldable arm.

Aligned with and fixed (as by bar 70 off bracket 69) to each footboard leg 53 is a special footboard actuating track 64. It is suitably slot-like in character, and is, for the most part, substantially straight and parallel with the footboard leg 53 with which it is associated. However, its terminal portion (i.e., than portion nearest the pivot attachment of the footboard legs to the base unit 10) takes a change of direction from the parallel. The terminal portion angles or veers toward a direction away from the base unit 10 (as compared to the straight path portion of the actuating track). In other words, the terminal portion 65 angles or veers away from the base unit 10 as observed when the footboard is in retracted or folded condition, in an out-of-way position adjacent the end of the base unit 10.

On tiltable platform unit 11 are mounted actuating members 66 (or pins or rollers) which cooperate with actuating tracks 64 of the footboard legs 53. As shown, the actuating members 66, or pins, are fixedly mounted to special guide parts 67 (i.e., slotted limit paths) fixed to the tiltable platform unit 11. Guide parts 67 are illustrated as bands or straps of metal forming a slot between them and the base of the tilt platform 46.

As the tilt platform unit 11 is initially moved in a horizontal direction toward the end of the apparatus where the footboard assembly 12 is located (see FIG. 8), the actuating member 66 on the tiltable platform unit 11 moves through the terminal sloped portion 65 of the actuating track attached to the footboard legs 53. This action simultaneously pivots the footboard legs 53 upwardly to a position substantially parallel with the horizontally-located tilt platform 46 (see dash lines in FIG. 7). It is important to recognize that, during this action, the tilt platform 46 is not tilting, but solely moves in a horizontal path. (It is, of course, permissible for this motion to be accompanied by a slight but more or less insignificant tilt, even though such is not desired at this stage of motion.)

Then, after the actuating member 66 passes out of the sloped terminal portion 65 of the footboard leg actuating track 64, continued horizontal movement of the tiltable platform 46 toward the footboard is accompanied by passage of the actuating member 66 along the parallel stretch of the actuating track 64.

It is at the time of initial movement of the titlable platfrom 46 in a horizontal direction toward the footboard assembly that several other movements occur in the footboard assembly. During this time (i.e., as the actuating member 66 moves in the sloped terminal portion 65 of the actuating track to elevate the footboard legs 53 to a horizontal orientation), the biasing action of the footboard leg springs 58 pulls slide members 57 toward the terminal pivot or hinged mounting 56 for the footboard. This simultaneously causes the footboard 54 to pivot outwardly at its hinged attachment 56 to legs 53. It pivots outwardly into a position substantially perpendicular to the legs 53 (and therefore perpendicular to the tiltable platform 46) after the legs are moved upwardly into the horizontal location. At the same time, brace arms 59 move into bracing position for the extended footboard.

Upon further horizontal shifting movement of the tiltable platform 46, as the actuating part 66 moves along the parallel part of the actuating track 64, the foldable arms 60 and 61 (between the tiltable platform 46 and the slide members 57 on the footboard legs 53) fold into the position illustrated by the dash lines in FIG. 7. Thus, they are out of the way during the subsequent tilting of the tiltable platform; and they are out of the way as a patient stands on the footboard when the tilt top is in the upright position.

After the position illustrated by the dash lines in FIG. 7 is reached, the platform 46 and footboard assembly 12 tilt as one unit. This is illustrated graphically in FIG. 9.

Reverse action lowers the tiltable platform 46 to the horizontal and simultaneously moves the footboard assembly 12 upwardly to place the footboard legs 53 in the horizontal position shown by dash lines in FIG. 7. After reaching the horizontal orientation, the tiltable platform 46 moves horizontally away from the footboard 54; and this is accompanied by an opening of the foldable arms 60 and 61. All of this occurs during the travel of the actuating member 66 in the parallel portion 64 of the actuating track on its way to the sloped portion 65. When the actuating member 66 moves into the sloped part 65 of the actuating track (see FIG. 8), the footboard legs 53 lower or move toward the out-of-the-way position as shown by the solid lines in FIG. 7. Simultaneously, the foldable arms 60 and 61 pull the slide members 57 upwardly along the footboard legs 53. The movement of the slide members 57 upwardly puts spring 58 under tension, pulls arms 59, and causes the footboard 54 to fold back to the out-of-the-way position illustrated by the solid lines in FIG. 7.

The fourth major grouping, called the major pivot assembly 13, will now be discussed. This provides the situs for the pivot action between the tiltable platform unit 11 and the base unit 10. Of course, a pivot connection between a tiltable platform unit 11 and base unit 10 could simply be hinge-type in character; and the basic tilt principles of the present invention (e.g., a linear-style cam track 47 and pusher 42) could be useful for such apparatus. But much more advantageous results are made possible by virtue of the floating pivot principle which is preferably employed. The special assembly taught herein, or a substantial equivalent, permits horizontal movement of the tiltable platform unit 11 with respect to the base unit 10 without loss of the necessary positive pivot connection between the two. Basically, to accomplish this requires a cooperative interaction between a. guide part 68 and a guide follower part 67, with one such part on the tiltable platform unit and the other on the base frame unit.

Referring to FIGS. 1, 2 and 9, the details illustrating this pivot action will be covered. Guide part 68, suitably consisting of a roller or freely rotatable wheel, is fixed on pivot shaft 55. Pivot shaft 55 is fixed to the base unit (i.e., to the top structure of the base unit 10) at the location where pivoting is selected to take place. If the guide part 68 is mounted at a location other than at the pivot shaft, the mounting of the guide part 68 must be such as to move in an arc (during the tilt action) having its center at the axis of the major pivot shaft 55. (But during horizontal shifting, guide part 68 would normally remain fixed, as to the base unit 10.) Generally, the location of the guide part 68 will be as illustrated in the drawing, at an upper end part of the top structure 15 of the base unit 10, and at a location coinciding with the axis of major pivot.

The guide follower part 67, is shown fixed to the tiltable platform unit 11. Guide follower part 67 is adapted to move over the guide part 68 within the limits of the horizontal movement selected for the apparatus. Usually two guide parts 68, laterally spaced at corner locations under the tilt platform 46, cooperate with two guide follower parts 67 on the tilt platform at laterally spaced locations, as illustrated.

Even without additional elements, guide part 68 and guide follower part 67 provide a necessary connection between the tiltable platform and base frame unit for a tilting operation consistent with horizontal relative movement between the units. But additional elements may be added to contribute to the formation of a positive interlock at the time of tilting, as well as to build in a safety factor against upsetting the tiltable platform (or overtilting it), as a person steps upon the footboard.

Reference is made to the schematic showing in FIGS. 10 and 11. Underneath the tiltable platform 46, at the end thereof horizontally movable over the axis or shaft of tilt, are a pair of lock bars 71 hingedly or pivotally mounted at one end thereof to a pin or pins 72 in or on the body of tiltable platform 46. These lock bars 71 are biased to cause their free upper or outer end to are or move away from a recess underneath the tiltable platform as the platform begins to move upwardly in tilting. A leaf or bar-type spring 73 between pin shaft 72 and a tie bar 74 (between the outermost ends of lock bars 71) biases the lock bars 71 to cause them to arc away from their recess under platform 46 toward pivot shaft 55. Each lock bar has a notch 75 in it which accommodates an element at the axis of pivot. Pivot shaft 55 serves as such an element. Thus, as the tiltable platform 46 is initiated in tilting action, lock bars 71 are away from it; and the notch 75 (or lock feature) of the lock bars 71 implants itself over the shaft 55 of the axis of tilt. This prevents any slipping of the tiltable platform unit 11 as might otherwise occur along the guide follower part during the actual tilting operation. In short, the tilting action causes the locking action of the lock bars 71. Conversely, as the tilted platform is returned to the horizontal, the lock bars are displaced upwardly under the platform 46 to release the pivot lock mechanism thereof. Tie bar 74 is of such width that it forms an abutment projection 76 which abuts against the top surface of the table top 36 of the base unit 10 as the tilt top 46 is returned to the horizontal. This action elevates the lock bars 71 to release the lock mechanism.

Safety against over-tilting is provided by spring means 77 which are put under immense tension during the very terminal portion of tilt movement. This extreme tension biases the tiltable platform unit and base frame unit toward each other. These springs 77 are fixed at their lower end to an element of the to part 15 of the base unit 10. Suitably, they are fixed to a lateral brace 37 (see FIG. 6). They extend up to a lift bar 78 which rests (when the tilt 10 top is horizontal) on the uppermost portion or table top 36 of the top structure 15 of the base unit 10. A hole or opening 79 in base top or plate 36 is provided for the springs 77. If desired, lift bar 78 may be fixed to arms 81 pivotally mounted, as at the pivot shaft 55.

Lift bar 78 does not move during horizontal movement of the tiltable platform. Indeed, it does not move or shift in position at all during most of the tilt movement of the tiltable platform. But at the very last portion of the arc of tilt movement, cam abutment members (on the interior of the major cams or track members 47 of the tiltable platform 46) strike against, or abut against, the ends of the safety lift bar 78 and raise it. This action places the springs 77 under immense tension and biases the tilt of the platform toward the horizontal. A heavy person stepping on the footboard, if he avoids leaning against the tiltable platform at the time he places his weight on the footboard, may cause the platform to move further toward the vertical. But the strength and the tension of the springs 77 are preferably such that, when he rests his body against the tiltable platform 46, the springs act to hold the platform against the means effecting tilt of it. Although a simple abutment (such as cam abutment 80 striking a fixed bar or abutment on the base unit 10), without any spring biasing, might be employed for this purpose, coordination of the position of a rigid abutment with the extent of tilt movement effected by a motor presents sufiicient problems of registry to justify the more flexible arrangement just discussed. Further, the use of springs 77, as illustrated, provides a biasing action during the last few degrees of upward tilt (and not solely at the terminus of upward tilt), where security against jerking motion or over-tilting caused by a nervous movement of a patient is most needed. The sense of feel allowed by the use of tension springs 77 thus causes a patient to have greater confidence as he is being moved.

An explanation will now be given for an illustrative electrical system, such shown in FIG. 12 (with parts shown in FIGS. 1 and 2). A male plug 82 is provided for hook-up to a power source. A control switch box 83 holds a height adjustability switch 84 separate from a tilt switch 85. This box 83 is of molded shape easily held in one hand.

Pressing height adjustability switch 84 in one direction (for raising top structure 15 with respect to base stand 14) closes a circuit through electrical lines 86 and 87, normally-closed maximum-up limit switch 88, line 89, motor 25, and lines 90 and 91. At the maximum-upward position, limit switch 88 is parted or broken to stop motor 25. Thus one may continually press height-adjustability switch 84 in the direction causing upward movement for so long as upward movement is desired; and the limit switch 88 serves as a safety factor to stop the upward movement before the tubular legs 19 are ejected from the base legs 28. Any fractional upward movement may be effected by releasing switch 84 when the desired height for the apparatus is reached.

Pressing height-adjustability switch in the reverse direction closes the circuit through lines 86 and 92, normally-closed maximum-down limit switch 93, line 94, motor 25, and lines 90 and 91. Motor 25 rotates in reverse direction when this circuit is closed, and serves to lower the height of the apparatus until either the switch 84 is released or the limit switch 93 is broken. Limit switches 88 and 93 for the height adjustability limits of movement for the base unit 10 are not shown in the drawing except in FIG. 12, but are suitably positioned in control box 21 of the base unit 10 and opened to break contact by adding an abutment member on bracket 23.

Movement of tilt switch in one direction (to cause tilting of the platform 46 to the upright position) closes the circuit through lines 86 and 95, normally-closed maximum-tilt limit switch 96, line 97, motor 45, and lines 98 and 91. Again, the degree of movement, in this case tilting movement, may be controlled by releasing tilt switch 85 at any time before reaching the maximum tilt position where limit contact 96 is broken by yolk switch breaker 108 to arrest further tilt.

To return the platform 46 to the horizontal, tilt switch 85 is pressed in an opposite direction, which closes the circuit through lines 86 and 99, normally-closed maximum-return limit switch 100, line 101, motor 45', and lines 98 and 91. This action causes reversible motor 45 to rotate in a direction opposite to that for achieving tilt.

Tilt switch 85 serves not only to control the tilt of platform 46 but also to control the horizontal shift movement of it. These movements may be arrested at any stage by releasing switch 85. When the platform 46 is in the position illustrated in FIG. 1 and by the solid lines in FIG. 9, the closing of the circuit to cause tilt serves initially to horizontally shift the platform 46 by causing yoke 39 to move along the path of tracks 33 and 34 on the base unit 10. This initial movement causes the cam pusher 42 to move from the solid line position in FIG. 9 to the dash line position in that figure.

The track provided by cam 47 includes a curved recess 102 (see FIG. 9) which rests over cam pusher 42. The weight of the platform 46, in combination with the low friction support for horizontal movement of platform 46, is sufficient to maintain the curved recess 102 of the track of cam 47 over the cam pusher 42 during horizontal movement of the cam pusher along the path of tracks 33 and 34 on the base unit 10. Thus, the horizontal shifting of platform 46 occurs during the initial movement of cam pushers 42; and tilting action takes place, with cam pushers 42 rolling along the curvilinear track at the lower edge of earns 47 (see FIG. 9), as soon as the limit of guide slot 67 abuts against guide member 68. At this point, horizontal movement ceases and cam pushers 42, which continue along the predetermined path set by tracks 33 and 34, move along the curvilinear track provided by the curved depending mass of cam elements 47 on the tilt platform 46. Thus, the tilt platform 46- is elevated into tilt position. Upward tilt causes the notch 75 of lock bar 71 to hook upon the tilt axis shaft 55-, as previously discussed.

The hook part or end 103 (see FIG. 9) of earns 47 serves as a catch on return of cam pushers 42 during the lowering of tilt top 46. Thus, after cam pushers 42 return (from vertical tilt) to the position shown in dash lines in FIG. 9, they pull tilt platform 46 horizontally to the position of solid lines in FIG. 9. In effect, the curved recess 102 (with hook part 103 on one side and the curvilinear depending track along the edge of cam 47 on the other) provides a temporary or releasable interlocking part for cam pusher 42. Thus, pusher 42 and recess 102 act together to form a cooperative interlock connection between the track means 47 and the track follower means 42. This connection makes possible the horizontal shifting movement, as discussed, during a portion of one end of the extremity of motion for track followers 42 along their path of movement.

The orientation of the platform unit in the upright position may be truly vertical, if desired; but in most cases, a slope of about up to about 30 from the vertical is preferred for patient comfort and confidence. In other words, the upright position most comfortable and least disturbing to patients is not truly vertical, but at an angle. This angle can vary greatly. However, an angle of only about 50 from the horizontal (40 from the vertical) is normally of such slight upright elevation that it, in most cases, is not adequate. Usually the upright position considered most acceptable to patients is around 70 or 75 from the horizontal. After a patient has been lying horizontally for a few minutes, the sensation he gets when moving to about 70 (or 75 or possibly 80) from the horizontal is that he is ending up in a truly vertical or upright position. But that same patient,

if moved to a truly or vertical position, gains the sensation of passing through a vertical position toward a position where he feels he is being over-tilted or pushed over the other way.

The speed or rate of movement for upward tilt of platform 46 is governed by the french curve track feature of cams 47. This track feature is quite important where the incremental movement of the yolk 39 and the track follower pushers 42 is uniform in rate along the length of the entire predetermined linear-style path for their movements afforded by tracks 33 and 34. Initially, as track pushers 42 roll over the gradual curve from notches 102 toward the maximum depending mass of cams 47, the rate of upward movement is very gradual for platform 46; but this rate of upward movement increases to a maximum rate as pushers 42 move along the tracks afforded by cams 47 toward the lowermost or maximum depending mass of earns 47 (as viewed in FIGS. 1 or 9). Continued movement of pushers 42 is along the terminal portions of the maximum depending mass of curved cams 47. The terminal portions assume a gradual curve upwardly (i.e. the terminal portions being nearest the footboard as viewed in FIG. 1). It is this terminal gradual upward curve of the depending mass of cam 47 which serves to slow the rate of tilt for platform 46 during the last few degrees of upward tilt movement.

Of course, an alternate way to achieve slower motion at the extremes of the tilt motion (both at the beginning of tilt and at the terminal portion of tilt) would be to adjust the rate of movement of pushers 4-2 at the terminal portions for their movement; and this, of course, would permit one to use a straight track for the edge of cam 47, which is quite possible, and thereby avoid a curvedtype track. It also, however, would normally be more expensive than the approach realized by use of the curved track 47 as illustrated and as preferred.

Especially to be noted is that the track afforded by substantially horizontal rails 33 and 34 on the base unit and the track afforded by the lower edge of large cams 47 are incongruent (that is not identical or purely parallel in orientation). Further, the track afforded by earns 47 lies in a vertical plane substantially parallel or aligned with the track means 33 and 3-4 of the base unit 10.

While the position of the major pivot axis shaft 55 may vary from that illustrated, it normally will be transverse to the tracks of both the base and platform unit and spaced outwardly from the terminus of the track means of at least one of the units.

As noted hereinabove, both the height adjustability switch 84 and tilt switch 85 may be placed on a single control switch box 83. The wire line or electrical cable 104 (see FIGS. 1 and 2) from this box may be coiled about a reel 105 on the end of an expansible or telescoping shaft 106. Thus, reel 105 may be pulled out for unwinding cable 104 and then pushed back to a recessed location where it is out of the way. A doctor or other operator may then hold switch box 83 in his hand and stand at the side of the apparatus while adjusting height or tilt, as desired. An electrical junction box 107 is suitably provided to tie the cables from the power plug 82 and the switch box 83 to motors 25 and 45.

That which is claimed is:

1. Tiltable platform apparatus comprising (i) a base unit,

(ii) a platform unit tiltable with respect to said base unit,

(iii) means comprising a pivot assembly connecting said units together,

(iv) linear-style track means on one of said units,

(v) track follower means movable in a predetermined linear-style path on the other of said units,

(vi) means to drive said track follower means in either direction along said predetermined linear-style path while maintaining said track follower means in cooperative relationship with said track means on said 13 one unit for traversing said track means, said predetermined linear-style path and said linear-style track means being incongruent, whereby traversing said track means with said track follower means tilts said platform unit with respect to said base unit.

2. Apparatus of claim 1 wherein said linear-style trac-k means is curvilinear and said linear-style path is substantially straight.

3. Apparatus of claim 1 comprising, in addition, means to shift said platform unit in a horizontal direction prior to tilting the same with respect to said base unit.

4. Apparatus of claim 3 wherein said linear-style path is substantially horizontal and straight, and wherein said means to shift said platform unit comprises a cooperative interlock connection between said track means on said one unit and said track follower means on the other of said units, whereby movement of said track follower means in a portion of one end of said predetermined path effects said horizontal shifting of said platform unit with respect to said base unit.

5. Apparatus of claim 3 wherein said pivot assembly comprises a guide part and a guide follower part cooperatively associated therewith, one of said parts being linearly-movable with respect to the other, one of said parts being on one of said units and the other of said parts being on the other of said units.

6. Apparatus of claim 1 characterized further in that said platform unit is elongated, said apparatus comprising, in addition, a movable footboard at one end thereof, means to move said footboard to a position substantially perpendicular to the plane of said platform unit at said one end, and means to withdraw and fold said footboard to a position along said one end below said platform unit.

7. Apparatus of claim 3 characterized further in that said platform unit is elongated, said apparatus comprising, in addition, an extensible and retractable footboard assembly including (i) a leg member pivotally attached at one end to said base unit at a location near an upper portion of said base unit proximate to one end of said elongated platform unit,

(ii) a footboard pivotally attached to the other end of said leg member,

(iii) a slide member adapted to slide along said leg member,

(iv) means biasing said slide member toward said footboard,

(v) a footboard brace arm pivotally secured at one end to said slide member and pivotally secured at the other end to said footboard at a location spaced from the pivot attachment of said footboard to said leg,

(vi) a foldable arm pivotally attached at one end to said platform unit and pivotally attached at the other end to said slide member,

(vii) an actuating member fixed to said platform unit,

(viii) an actuating track fixed to said leg member, said actuating track being parallel with said leg member except for a terminal portion thereof proximate to the pivot attachment between said leg member and said base unit, said terminal portion being in an angular direction outward from said base unit as observed when said footboard assembly is retracted,

whereby initial horizontal shift movement of said platform unit, moves said actuating member along said terminal portion of said actuating track to raise said leg member to a position substantially parallel with said platform, simultaneously causing said slide member to slide under action of said biasing means toward the pivot attachment of said leg member to said footboard, which simultaneously causes said brace arm to extend said footboard to a position perpendicular to said leg, after which, further horizontal shift movement of said platform unit toward said extended footboard moves said actuating member along the portion of said actuating track 'which is substantially parallel with said leg and folds said foldable arm connection between said platform unit and said slide member.

8. The apparatus of claim 1 wherein said base unit comprises a lower stand member and an upper frame member and includes means for adjustment of the height of said upper frame member with respect to the lower stand member.

9. The apparatus of claim 8 wherein said means for height adjustability is operable independently of the means for tilting the platform unit.

10. Apparatus of claim 5 wherein said pivot assembly additionally comprises a major pivot shaft fixed to said base unit, said guide part of said pivot assembly being fixed in relationship to said major pivot shaft.

11. Apparatus of claim 10 comprising, in addition, a movable footboard at one end thereof, two leg members extending between pivot connections of the same to said footboard and said major pivot shaft, said footboard being normally withdrawn and folded along one end of said apparatus below said platform unit, and means to pivot said footboard legs and simultaneously move said footboard to a position substantially perpendicular to the plane of said platform unit at said one end during said shifting of said platform unit in a horizontal direction a prior to tilting the same.

12. Tiltable platform apparatus comprising (i) a base unit carrying substantially horizontal linearstyle track means,

(ii) a platform unit tiltable with respect to said base unit, said platform unit carrying linear-style track means incongruent with respect to said track means of said base unit but lying in a vertical plane substantially parallel with said track means of said base unit,

(iii) means comprising a pivot assembly connecting said units together, said pivot assembly including a major pivot axis transverse to said track means of said units and spaced outwardly from the terminus of the track means of at least one of said units,

(iv) a truck assembly mounted on one of said units, said truck assembly including track follower means,

(v) means for driving said truck assembly in either direction along the track means of one of said units with the track follower means of said truck assembly simultaneously traversing along the track means of the other of said units, thereby to tilt said platform unit about said major pivot axis.

13. Apparatus of claim 12 wherein said linear-style track means of said platform unit comprises a curved track depending below said platform unit and fixed thereto.

14. Apparatus of claim 12 comprising, in addition, means to shift said platform unit in a horizontal direction prior to tilting the same with respect to said base unit.

15. Apparatus of claim 14 wherein said means to shift said platform unit comprises a cooperative interlock between the track means of said one unit and said track follower means during a portion of the movement of said truck assembly.

16. Apparatus of claim 14 wherein said pivot assembly comprises a guide part and a guide follower part cooperatively associated therewith, one of said parts being linearly-movable with respect to the other, one of said parts being on one of said units and the other of said parts being on the other of said units.

17. Apparatus of claim 16 wherein said guide part of said pivot assembly is fixed to said major pivot axis.

18. Apparatus of claim 12 characterized further in that said platform unit is elongated, said apparatus comprising, in addition, a movable footboard at one end thereof, means to move said footboard to a position substantially perpendicular to the plane of said platform unit at said one end prior to tilting said platform unit, and means to withdraw and fold said footboard to a position along said one end below said platform unit after returning said platform unit to the horizontal from a tilt position.

19. The apparatus of claim 12 wherein said base unit comprises a lower stand member and an upper frame member and includes means for adjustment of the height of said upper frame member with respect to the lower stand member.

20. Apparatus comprising two units shiftable with respect to each other in a predetermined path one of said units being a base, and an extensible and retractable assembly including:

(i) a leg member pivotally attached at one end to one of said units,

(ii) an actuating member fixed to one of said units, and

(iii) an actuating track fixed to said leg member, said actuating track being in a plane perpendicular to the axis of the pivotal attachment of said leg member to said one unit, whereby, as said units are shifted with respect to each other, said actuating member traverses said actuating track to extend or retract said leg member depending upon the direction of shift between said units.

21. Apparatus of claim 20 wherein the other of said units is a platform, said apparatus including means for tilting said platform with respect to said base unit.

22. Apparatus of claim 21 wherein said means for tilting said platform comprises a curved track member on said platform unit and means on said base unit for moving a track follower member for cooperative action with said curved track member during said tilting.

References Cited UNITED STATES PATENTS 2,120,732 6/1938 Comper et a1. 269323 2,306,031 12/1942 Anderson et al 269323 2,534,623 12/1950 Pitts et a1. 269323 2,680,046 6/1954 Stava 269-323 2,771,330 11/1956 Zaalberg 269-323 2,816,806 12/1957 Zaalberg 269323 2,828,172 3/ 1958 McDonald 269--323 2,887,691 5/1959 Talarico et a1. 562 3,283,732 11/1966 Oja et a1. 563 3,525,308 8/1970 Koopmans 1088 20 CASMIR A. NUNBERG, Primary Examiner US. Cl. X.R. 269323; 297434- 

